For many thousands of years, people have been going up and down mountains. Since people began wearing shoes for this activity, the footwear has evolved. In skiing, footwear has changed from skin boots filled with fur, felt or grass to modern cast polymer shells enclosing a padded liner. The sole of the boot can be rigid along its length or more flexible for different types of skiing. In mountaineering, old hobnail leather boots have given way to modern leather or polymer constructions with a treaded sole of rubber compounds or polymers.
The foot is a complex mechanical appendage. The human foot consists of 26 bones and is arranged into several regions. The heel region consists of the heel and ankle bones. The midfoot has five irregular bones and describes an arch, that in combination with ligaments and muscles serves as a shock absorber. The forefoot consists of the long metatarsal bones and the toes. The region of the bottom of the foot where the toes meet the metatarsal bones is a padded feature referred to as the ball of the foot.
Unlike the padded paws of dogs or the hoofed feet of horses, the human foot is remarkably versatile and is equally good as a platform upon which a person can steady themselves to lift great weights, or limber enough for someone to scale a great coconut tree to retrieve fruits from the treetop. The human foot can be controlled to become a rigid pivot for a ballerina or as a flat sensitive surface for a high speed race car driver, through which vibrations and feedback can be detected.
The toes are essential for human locomotion such as walking, running and jumping. The toes are where the forward motion of a human being is energized by transferring energy from the toes to the ground. The human toe has a normal range of motion between eighty degrees above the horizontal prone position and a downward range of twenty degrees. Runners dig in their toes with an upward bend of up to eighty degrees then explode from the line and accelerate by using the toes to apply downward pressure on the ground. This downward pressure is maximized as the toes approach eighty degrees of flexure and is released as the toes return to the prone position. The toes are sufficiently strong enough to withstand the forces involved. Sprinters rely on the flexure of the front of the foot for control, comfort, speed and acceleration. Boxers tend to balance on their toes for optimal maneuvering. The overall flexibility, design and strength of the human foot are performance enhancing assets and essential for control.
In downhill skiing, snowboarding and mountaineering, the boot sole is inflexible, reducing the inherent performance of the foot by restricting toe flexibility. The only toe flexibility possibility is from curling the toes downward to twenty degrees below the prone position. These boots do not permit upwards flexure to eighty degrees and therefore prevent a maximization and optimization of downward toe pressure.
By way of further background, FIG. 1 is a partial cross-sectional view of a conventional ski boot 100, in which the lower shell of the boot 102 has been cut away to expose the inner liner 104 and a representative foot 106. The toe region 108, ball of the foot region 110 and the heel 112 (not shown) are coplanar and parallel to the line of the horizontal plane HP1 relative to the ski (not shown), whether going downhill or on the level. This is not an optimal use of the foot because the toes are not able to be flexed upwards toward eighty degrees relative to the center of gravity.
FIG. 2 is a side view of a representative foot 200, showing the range of possible flexure of the toes 202, from the center of the ball of the foot region 204. The toes can be flexed upwards from the horizontal plane HP2 through an arc of motion 206 to a maximum angular toe orientation 208 relative to the horizontal plane HP2 that describes an elevated angle of eighty degrees (80°). In a similar fashion, the angular toe orientation 210 describes an elevated angle of sixty-five degrees (65°). The angular toe orientation 212 describes an elevated angle of forty-five degrees (45°). The angular toe orientation 214 describes an elevated angle of thirty degrees (30°). The angular toe orientation 216 describes an elevated angle of fifteen degrees (15°). The angular toe orientation 218 describes an elevated angle of ten degrees (10°). The angular toe orientation 220 describes a declining angle of fifteen degrees (15°) below the horizontal plane HP2. These elevations and declinations are representative of the multiple orientations of the toes in their normal full range of motion. This vast range of possible toe positions is essential for human movement, whether as a sprinter, rock climber or a dancer. But conventional ski boots prevent the toes from flexing to the optimal position for applying downward pressure by locking the toes in the prone position.
It is desirable, therefore, to provide a structure that is either removable, adjustable or integral to the boot system, which allows for reorientation of the toes so that they are better positioned to carry out the tasks of either skiing, snowboarding or mountaineering going downhill on inclined terrain. This structure and the associated functionality it provides will make possible the increased use of the toes in skiing and/or mountaineering for greater control, comfort and safety.